Welcome to Bimmerfest -- The #1 Online Community for BMW related information! Please enjoy the discussion forums below and share your experiences with the 200,000 current, new and past BMW owners. The forums are broken out by car model and into other special interest sections such as BMW European Delivery and a special forum to voice your questions to the many BMW dealers on the site to assist our members!

New cell, I use it until totally drained, then charge 4-5 hours (per manual)
The phone reads fully charged on screen, and battery charge indicator bars after 2 hours-fully charged really????
Car charger same, yet charge lasts for a shorter period of time.
3 days charged at home, 1 day charged in car.
Any ideas?
New phone- if anything overcharged for the first 2 charges then one car charge, one home charge, now on home charge again. (trying to be thorough)
I realise there are some who believe in rechargable battery "memory"
I also remember reading in either Sail magazine or Cruising and the writer saying that NASA did tests and batteries don't have memory.
Maybe we should just plug them in every night at home.

It could be showing fully charged when quick-charge cycle is complete.... after which it gets slow charged? I know if I charge my phone on my desk charger until it stops flashing that it's charging, it won't last as long as if I left it there overnight or something like that....

Many chargers and phones are designed to take the phone to 80% charge quickly and call it full. The remaining 20% charge is done much more slowly. Charging the battery quickly tends to heat it up and I seem to remember reading that it was difficult to get a full charge quickly. Only NiCd seems to handle quick charges relatively well.

__________________

-Peter

"Never attribute to malice that which can be adequately explained by stupidity."

Batteries do have "memories". NiCd batteries if you don't completely discharge them before recharging will hold less of a charge the next time. Kind of a pain for a cell phone since you never know when the battery will totally crap out. Li batteries from what I have been told do not suffer from this problem as long as you do as Kaz suggested and totally cycle the battery 3~4 times. From there you can charge it whenever supposedly with no ill effects.

I too have found that the car charge doesn't last very long and believe it is the quick-charge vs slow/deep charge you get from the wall charger.

__________________

"In the long history of the world, only a few generations have been granted the role of defending freedom in its hour of maximum danger. I do not shrink from the responsibility...I welcome it!" - JFK

Thanks guys.
I have the newer battery and try to discharge it totally before recharging, other than the one quick car charge I have totally drained it going on 4 times probably this Thurs.
I keep calling an old office # that's been shut off until it dies, when home and battery very low.
Yeah...I'm anal sometimes.
After this upcoming deep charge I'll just live with whatever I get, and hope for deep charge.
Knowing no memory will help me sleep though.
Just kidding-I'm not quite that bad.
Thanks again

- NiCd batteries are the first technology that was used on cell phones, it is almost no longer used (environmental concerns over Cd). These batteries take very well quick charges but they do suffer from memory effect.
For info on memory effect: if your battery is only 60% charged (or 40% discharged) and you charge it, then during the next use, you will only have 40% of the battery capacity available, getting the last 60% out of the battery will be difficult and you will have to discharge in several sessions
- NiMH are a technology similar to NiCd, but using metal hydride instead of Cd, and it was developpped so as not to have memory effect. It is now quite cheap and efficient, albeit batteries are still on the heavy side.
Both NiCd and NiMH have the advantage to be able to be charged at constant current only (no need for voltage control) and to be able to charge rather quickly.
- Lithium: these are light batteries, high capacity. No memory effect, but they need to be charged by constant current followed by constant voltage (of about 4.1 or 4.2V).

The charging process may be different between all 3 technologies, but the principle remains the same that it is easy to stuff a lot of energy at the beginning of the charge into the battery, a lot more difficult at the end (think of filling in a bucket of water as quickly as possible without spilling, you always have to slow down towards the end, right?). So, getting to 80% charge quickly is easy, getting from there to 100% takes time. Car chargers are usualy charging at higher current hence they charge quicker to the 80% mark than home chargers, but when it comes down to the last part of charging, home and car chargers are about equal. Note that car chargers, if used frequently, are usualy shortening the life of the battery as quick charges are detrimental to the battery.

As a conclusion: memory effect is only for NiCd, and nowadays, almost no phones are using that technology, so no cell phones should have memory effect any more.

Nice reply, thank you for your time.
Now pretend you're talking to a five year old. (40 something with the brainpower of Bullwinkle the Moose)
Should I wait until battery is ALMOST dead and charge at home (which seems best), or my battery having no clue, charge it up every night?
For what it's worth:3.7v Li-ion polymer . That is what I read on my battery.
Thanks!